groups: Print group names a user is in
groups prints the names of the primary and any supplementary
groups for each given username, or the current process if no names
are given. If more than one name is given, the name of each user is
the list of that user’s groups and the user name is separated from the
group list by a colon. Synopsis:
The group lists are equivalent to the output of the command ‘id -Gn’.
The only options are --help and --version. See Common options.
Primary and supplementary groups for a process are normally inherited
from its parent and are usually unchanged since login. This means
that if you change the group database after logging in,
will not reflect your changes within your existing login session.
groups with a list of users causes the user and group
database to be consulted afresh, and so will give a different result.
An exit status of zero indicates success, and a nonzero value indicates failure.